Month: July 2016

Caption: In March 1965, Russian Alexei Leonov (1934–) nearly died during the first ever spacewalk. (Image from “The Moon,” original Russian title ЛУНА, 1965)

(Not) Freezing in Space

A young man who attended my presentation “Your Future Space” at the Tyler Junior College Planetarium June 25 asked if astronauts are in danger of freezing during spacewalks.

The temperature in space is about 250 degrees F (121 C) in the sun, and about -250 degrees F (-157 C) in the “shade.” But the real danger of freezing is not from the cold. A body exposed to vacuum, in the sun or shade, will freeze-dry as all the air and liquids boil away.

However, astronauts are much more likely to overheat than freeze because spacesuits and space vehicles are insulated and sealed to prevent exposure to vacuum. (See NASA’s “Staying Cool on the ISS.”)

In fact, the first spacewalker, Russian Alexei Leonov, almost died of heatstroke. Like a sealed snack bag taken on up an airplane, his spacesuit ballooned out. Bending fingers, arms or legs against this pressure requires tremendous strength. Leonov had to release air from the suit to bend enough to get through the hatch and then close it.

Caption: At 11.500 feet in our Cessna 182 (see altimeter), the air trapped in the potato chip bag expands outward because the air in the cockpit presses on the bag about 35 percent less than at sea level. This ballooning effect is even more pronounced in the vacuum of space. (Photo by Marianne Dyson.)

Leonov perspired so much that once on the ground, “his sweat was now sloshing around in the suit, up to his knees.” (See BBC’s “The First Spacewalk.”)

Modern-day spacesuits use a lower pressure and don’t balloon out as much as Leonov’s did, and they fit through the hatches just fine. But astronauts still work up a sweat. As Scott Parazynski noted in an interview, “It takes quite a bit of effort [to move] … When you’re moving a spacesuit that is fully loaded with tools, and your own personal bodyweight, and the things you have in your backpack, it’s about 630 pounds’ worth of mass.” (Gwynne Watkins, “An Astronaut Fact-checks Gravity.”)

To stay cool, spacewalkers wear special long underwear filled with about 300 feet (91 m) of water-filled tubes. Astronauts can stop the flow if they get too cold. (Space Station Science, page 81).

People and equipment produce a lot of waste heat that builds up inside spacecraft as well. To keep spacecraft from overheating, fans blow hot air over cold tubes of water in what is called a heat exchanger. The water tubes are then cooled by ammonia in another heat exchanger. (Because ammonia is toxic, heat is not transferred directly from the air to the ammonia.) The giant white radiator panels on the International Space Station are filled with tubes of ammonia that radiate their heat into space.

So though there is a danger of freezing in space because of the vacuum. But spacesuits and spacecraft are designed to keep the air, and astronauts, comfortably cool.

Writing about Space

My story, “Fireworks in Orbit,” is about what might have happened if the space shuttle’s cooling system failed during a spacewalk. Originally published in Analog, it is reprinted in Fly Me to the Moon and Other Stories, available via CreateSpace or as an eBook via Amazon. For autographed copies, visit my website or find me at one of the events below.

Speaking about Space

Look for me at the following events. Watch my website Contact page for updates & Twitter for photos.

My experience with space sickness is documented in Science Fiction versus the Real Thing: What I learned on NASA’s “Vomit Comet,” available from Amazon for $1.79.

Will Space Make You Sick?

Astronauts don’t like to talk about it. Space tourist companies downplay it if they mention it at all. But about half of all people who go into space throw up. Some remain nauseous for days. Senator Jake Garn famously was space sick during his entire space shuttle flight in 1985.

Why do even fighter pilots get space sick? The answer is in the official name: Space Adaptation Syndrome.

Though I haven’t (yet) been into space, I have been space sick compliments of NASA’s aircraft, the “Vomit Comet.” I can assure you it is aptly named!

In 1999, students from the University of Illinois asked me to write about their participation in a NASA program (which is no longer funded) for Ad Astra, the magazine of the National Space Society. I happily agreed, got my flight physical, attended classes, and then flew 42 parabolas with them.

Caption: NASA’s “Vomit Comet” is like a roller coaster in the air, providing up to 25 seconds of freefall or acceleration equal to lunar or Martian gravity during each parabola.

When you go into freefall (see November 2015 Science Snacks for why I don’t say “zero g”), it’s like pushing on a door that suddenly opens. Blood and water go flying toward the head. Eyelids get puffy and noses get stuffy. The fluid in your inner ears, that tells your brain which way is down, floats. Yet your eyes still see the floor as down. This mismatch causes motion sickness in some people.

Also, the heart pumps blood “uphill” to the brain. Muscles in the blood vessels prevent the blood from falling back down too fast. When a person jumps off a high dive, or falls inside a spacecraft, the blood returning from the brain floats instead of falling. So like a bathtub with a small drain, blood accumulates in the head, putting pressure on the brain.

The brain quickly tries to reduce pressure by getting rid of water. Thus your body temperature rises and you break out in a sweat. You need to pee. And you might throw up. I sure did!

To feel the effects, stand up and bend over at the waist. Look at your face in a mirror. It will turn red, and your eyes will get squinty (but some wrinkles will disappear!). Your nose will feel stuffy (which is why astronauts sound like they have a cold and prefer spicy foods in space). You may start sweating (bend over to warm up if you’re ever chilly). After a few minutes, straighten up. As the blood rushes back down, you’ll feel lightheaded. This is how it feels to return from space (and why you might faint after landing).

Will you get space sick? Probably. But the good news is that repeat fliers report shorter adaptations. The brain “remembers” to ignore the ears. And most astronauts feel fine by the second day. This is why I’m not anxious to go on a suborbital flight, but I’d consider a two-week vacation in space, preferably including a swing around the Moon! And I’m not sorry I flew on the “Vomit Comet.” The sickness didn’t keep me from having fun testing my telekinetic “Jedi” powers on a floating Yoda! (Read the eBook to learn more.)

So this summer, if you want to prepare for your future flight into space, head for the high dive, the roller coasters, and maybe do some sky diving.

Writing about Space

Looking for some space-related nonfiction or science fiction to read this summer? Check out the hundreds of recommended books on National Space Society’s Reading Space. I’m happy to say that Trajectories, an anthology containing a new Mars story of mine, is included on the list. I hope you’ll check it out!

Speaking about Space

Look for me at the following events. Watch my website Contact page for updates & Twitter for photos.

Howdy, and a special welcome to those of you who subscribed via the Rice/Ride Family STEM Festival, the Texas Library Association conference, or the Ohioana Book Festival in April. I hope you enjoy your first science “snack.”

How might a future Martian prove to skeptics back on Earth that she is really on Mars?

This question is addressed in my story, “Dropping the Martian Ball” included in The Callahan Kids: Tales of Life on Mars anthology. The main character, eleven-year-old Mariah, is challenged by a “celebrity teen” on Earth to prove that her recording of a trip to visit the Viking 1 lander is not actually being faked from Utah.

Mariah performs a demonstration similar to the hammer and the feather drop done by the Apollo 15 astronauts (Scott and Irwin) on the Moon in 1971. Because gravity pulls on all objects equally, they fall at the same rate and impact the surface at the same time—unless there is a layer of air to slow them down, in which case the shape becomes very important! The Moon has no air, and so a feather and a hammer, or anything else dropped from the same height, fall and hit the dust at the same time. (Watch the Apollo video.)

Mariah drops a ball and feather and challenges someone to try this in Utah and compare their results.

Want to try it, but don’t have a feather? You can use paper to demonstrate air’s effects on falling objects. First, drop two sheets of paper, holding them horizontally. Observe how they flutter to the floor, arriving at the same time. Then crunch one up (changing its shape) and drop both sheets again. Guess which one hits the floor first?

Even though this demonstration proves that the shape/area and not the weight is what slows the feather, some people hold on to the misconception that heavier objects fall faster. To further convince them, drop two identical tubs with lids. Then place a heavy object like a battery in one while leaving the other empty. Drop both again. (Note that the more massive one impacts the surface with more force and may leave a dent because Force=Mass times Acceleration.)

Mariah uses the sublimation of water into the thin atmosphere as additional proof that she’s on Mars. Her brother shows how far he can hit a baseball in the lower gravity—with almost disastrous consequences. The different brightness/size of the sun, the lack of a global magnetic field, the curvature of the horizon, the change in temperature with height, or the passage from west to east of the moon Phobos might also have been used to demonstrate their presence on Mars.

Get 10 percent off print copies of The Callahan Kids anthology containing my story “Dropping the Martian Ball,” using a code on www.mDyson.com/4mars.

As Mariah discovers, some people will never be convinced of the truth no matter what evidence is offered as proof. But you can decide for yourself what to believe by doing experiments, checking facts using multiple sources that include peer-reviewed references and bibliographies, and asking questions of experts associated with academic or government institutions.

So though Mariah’s story is fiction, I hope you’ll try her experiments on Earth so you’ll be ready to respond to the skeptics when you visit Viking on the real Chryse Planitia. Be sure to check for the letter “B” that Astronomer Carl Sagan noticed on a nearby rock. Do you think it was carved by aliens?

Writing about Space

As a special promotion for my recent appearances, Springer is offering a 20 percent discount on print (regular price $39.99) or eBook (regular price $29.99) copies of my memoir, A Passion for Space, until May 19. Go to the springer.com website page for the book and enter the following code: xykH7xQj9MGQTx5.

Speaking about Space

Look for me at the following events. Watch my website Contact page for updates.

Hello, and a special welcome to those of you who subscribed after my visits to the University of Florida’s Society of Women Engineers in Gainesville and the Frontiers of Flight Museum in Dallas in March. This month’s science “snack” celebrates the 35th anniversary of the first Space Shuttle flight.

Caption: New Women Flight Controllers exhibit at the International Women in Aviation and Space Museum in Cleveland, Ohio, includes my donated STS-1 FAO console copies of Ascent and Entry Checklists, my pink STS-1 badge, and a copy of my memoir, A Passion for Space, that details early shuttle flight operations. Thanks to Museum Board Member Marcy Frumker and Executive Director Heather Alexander for creating this exhibit to help inspire the next generation of flight controllers. Photo by IWASM, 2016.

STS-1 Mission Control

April 12, 2016 is the 35th anniversary of the first Space Shuttle launch. My husband (Thor) and I were privileged to be part of the Mission Control team at Johnson Space Center. Thor, training to become a Guidance Officer, served as Winds. I was Timeline, training to become a Flight Activities Officer. What was it like to be flight controllers?

My memoir, A Passion for Space, has a detailed account, but the short answer is, “Cool!” For a pair of physicists who like solving mysteries and learning new things, it was the best job in the world.

A favorite memory from STS-1 was the first TV download of the payload bay. Violent shaking during launch had dislodged wayward bolts and washers that floated out. (Remember from my November 2015 Science Snacks: things float in space because of freefall, not because there isn’t any gravity!) Also visible were dark areas on the engine pods where thermal tiles had shaken off.

Caption: The first television broadcast from the Space Shuttle (during its second orbit) showed a majestic view of Earth from space after the successful launch and opening of the payload bay doors, but also the dark squares of tiles missing off the orbital maneuvering pods on either side of the tail. (White dot is reflection in window.) NASA image, 1981.

I reacted to this transmission in typical flight controller fashion, with both awe and concern. Awe that the world’s first winged spaceship and its crew (John Young and Robert Crippen) had survived a never-before-tested launch on top of a giant fuel tank with boosters strapped to either side, and then proceeded to successfully open its ungainly doors to provide cooling and access to space. Amazing!

The concern was for what we didn’t know. The missing tiles were not in a critical area, but as we’d learn tragically in 2003, a hole in the wings or underside could cause Columbia to burn up during entry.

We didn’t yet have an arm to peer over the side, so management worked with the military to scan the underbelly of the orbiter. Flight controllers helped determine timing to get the lighting, orientation, and ground track just right for telescopes. Unfortunately, clouds interfered with data collection.

Thus flight controllers anxiously watched for signs of equipment overheating during the entry on April 14, 1981. With no relay satellites (first deployed on STS-6 in 1983), they endured 20 minutes of communications blackout during entry through the upper atmosphere.

We all breathed a sigh of relief when data resumed and showed them “perfectly nominal.” Young and Crippen landed safely in California. They returned to Houston later that day, and Thor and I joined the crowd to welcome our heroes home.

To learn more about the historic Space Shuttle Program, I encourage you to read books and visit exhibits at museums and NASA centers. (Or ask me questions at one of the events below!) And if you like solving mysteries and learning new things, you might try becoming a flight controller. It’s definitely a cool job!

Writing about Space

The anthology, Trajectories that contains my story, “The Breath of Mars” is now available. If you order after using the link from my website, I get a credit from Amazon and you get a big THANK YOU!

Speaking about Space

Look for me at the following events. Watch my website Contact page for updates.

Hello, and a special welcome to those of you who subscribed after my visits to NASA Glenn’s AIAA section and the International Women in Aviation & Space Museum in Ohio in February. I look forward to sharing space stories with you, and seeing some of you again at upcoming appearances (listed below). I hope your brain enjoys its science “snack” this month!

Caption: I played Tour Guide for the American Engineering Geologists’ visit to Space Center Houston February 13.

The Gravity Question

Later this month, I’ll be doing the activity on pages 60-61 in Welcome to Mars (coauthored with Buzz Aldrin) comparing Earth with Mars with 60 girls attending a spring break STEM camp at the Frontiers of Flight Museum in Dallas. The activity compares the two worlds by diameter, volume, and mass. Considering Mars is one half as wide, one sixth as big, and one tenth as massive, why then does a person on the surface weight about one third as much as on Earth?

The answer is because weight is a measure of gravity’s downward pull, and gravity depends on two things: mass and (the square of) the distance from the center of mass. To avoid any messy math, I suggest using “Earth” units. In other words, the radius of Mars is simply half the radius of Earth versus 4,221 miles; and the mass is simply one tenth that of Earth versus 7 followed by 20 zeroes in tons!

Fortunately, calculating gravity does not require any fancy equations, just multiplication and division. Gravity equals a constant (G) times the mass (M) of the world divided by the square of the distance (R)(R) from the center of mass. Gravity of Earth=GM/R². So gravity of Mars in Earth units equals G (0.1M)/(0.5R)(0.5R). If we then divide that by Earth’s gravity, the G, M’s, and R’s all cancel out to 1, and we’re left with 0.1/(0.5)(0.5)=0.4. The actual value (in the “The Facts” table on page 61) is 0.37 which is most often rounded to one third.

Note that the gravity of the Moon (which is one hundredth the mass and a quarter of the radius) is (0.01M)/(0.25R)(0.25R) which is 0.16, about one sixth of Earth.

To feel how much something weighs on Earth versus on Mars or the Moon, fill three plastic bags or Easter eggs with 100 pennies or nickels for Earth, 37 for Mars, and 16 for the Moon. I wonder if shoes would last three times longer on Mars? Or would we just decide to go barefoot?

Writing about Space

The anthology, Touching the Face of the Cosmos: On the Intersection of Space Travel and Religion that contains my story, “The Right of Interference” is now available in paperback. If you order after using the link from my website, I get a credit from Amazon and you get a big THANK YOU!

Speaking about Space

Look for me at the following events. Watch my website Contact page for updates and local (Houston) events.

Hello, and thanks for subscribing to my monthly Science Snacks newsletter. I hope to see some of you at my upcoming appearances (listed below) and share space stories with you!

The Colorful Martian Sky

In the January Science Snacks, I discussed the recent discovery of liquid water on Mars and that several pages of Welcome to Mars (coauthored with Buzz Aldrin) are being updated to reflect the discovery. The changes (to pages 12 and 70) weren’t ready in time to be included in the second print run.

But the second printing (on right in image) does include rotation of the robots on the cover flap, and a change to the Martian Home art on pages 80-81.

Caption: The Martian Home art depicts a scene from a future settlement where kids enjoy Buzz’s favorite coconut ice cream (note the goat and a coconut palm!) at his Ice Cream Parlor while adults dine at my Pasta Palace. The question is, should the sky above be pink or blue?

The “true” color of the Martian sky has been debated since the first spacecraft sent back images from the surface. Most NASA images show a pink or butterscotch sky. This color results from dust suspended in the atmosphere, similar to dusty or smoggy skies on Earth. But dust also scatters blue light, as seen in sunset photos taken by the rover Spirit. And under some conditions, such as when ice clouds form, the sky may appear violet (see images).

converted PNM file

Caption: This sunset seen by Spirit in March 2014 appears blue near the sun and pink farther away. The sun is also about two thirds the diameter and less bright on Mars than it appears from Earth. (MER, Texas A&M, Cornell, JPL, NASA photo)

The scene depicted in the Martian Home art may be from a buried habitat with an artificial sky. (As noted on page 75, “Under 16 feet of dirt, we’ll get the same amount of radiation we get on the surface of Earth.”) Or the art might reflect the sky after terraforming has thickened the atmosphere as shown in the Green Mars art on pages 88-89.

However, to be consistent with the cover illustration showing a future Mars city under a dome (that protects from radiation via coatings or clear gel of some kind) with a lovely pink sky in the background, we decided to recolor the illustration on pages 80-81.

While researching this topic, I answered another question about the sky on Mars—do the stars twinkle there at night? The answer: no, the air is too thin. (“Why do stars twinkle, and do they twinkle on Mars?” by Whitehead, Hizinga, and Mossman, American Journal of Physics, 2012) But, if you observe from inside the Mars Home dome, would they twinkle? Let’s build one and find out!

Writing about Space

The anthology, Touching the Face of the Cosmos: On the Intersection of Space Travel and Religion that contains my story, “The Right of Interference” is out via Kindle and will be available in paperback March 1. If you order after using the link from my website, I get a credit from Amazon.

Speaking about Space

I’ll be speaking at the following events. Watch my website Contact page for updates and local (Houston) events.

Friday, February 19, speaker for “Dinner with a Slice of History.” International Women in Air & Space Museum, Burke Lakefront Airport, 1501 North Marginal Road, Cleveland, OH 44114. Open to the public. Tickets $15-17. Proceeds benefit museum.

Hello, and a special welcome to the new subscribers who signed up at Kennedy Space Center. Each month I pick one short science news or fact to share. I hope to see many of you again at future space or writing events where we can discuss our space stories!

Buzz & I signed Welcome to Mars at Kennedy Space Center on December 19, 2015 with help from Christina (Santa hat), & ShareSpace team of Linn, Rob, & Bob.

Liquid Water on Mars

On September 28, 2015, Georgia Tech grad student Lujendra Ojha published her evidence of liquid water on the surface of Mars. That same week, the first print run of Welcome to Mars was nearly sold out. Our editor at NatGeo suggested we reflect the water discovery in the second print run. So I asked myself, what impact does finding liquid water have to our plans to settle Mars?

It wasn’t news that there is water on Mars. Astronomers have observed the polar ice caps wax and wane with the seasons for more than a century. The Viking landers photographed frost forming on the surface. The Mars Phoenix Lander released video of ice sublimating (vaporizing) from the soil underneath its thrusters. The Curiosity rover found sufficient ice in the dirt that 3 cubic feet (0.08 m3) when heated, would produce enough water (6 pints or 2.8 L) for a person for a day.

Additionally, there is ample evidence from orbiting spacecraft that Mars once had oceans. Many have speculated that some of this water remains in underground aquifers.

But no one expected to find liquid water ON THE SURFACE of Mars!

The atmospheric pressure is so low, and the temperature so cold, that exposed water ice should instantly sublimate like we saw with the Phoenix lander.

But Ojha’s analyses of Martian surface features called Recurring Slope lineae (RSL) show water does flow on the surface. The salts in the water act like antifreeze and allow it to be liquid at temperatures below freezing.

Caption: Recurring Slope Lineae (RSL), on Horowitz Crater in southern hemisphere of Mars (32 degrees south latitude, 141 east longitude), appear as dark streaks about the length of a football field. Image credit: NASA/JPL-Caltech/Univ. of Arizona.

Finding water on the surface indicates that water is even more abundant than predicted. This is good news and may expand possible sites for future settlement. Or not. The presence of liquid water also increases the chances of finding alien microbes on Mars. If microbes are confirmed, is that a reason to slow or halt human settlements so as not to contaminate them or be contaminated by them?

The answer to this question depends on the nature of the Martian “bugs” and what they need from their environment to survive. Once we know that, we can determine if our use of, or changes to “their” water or minerals or energy source would be of benefit or harm to them or to us. But just knowing that something can live on Mars as it exists today would be very encouraging to our own long-term survival potential there. After all, our bodies have more microbes than human cells!

Yet I fear that because of our history, going back to the Martian canal controversy (1905), the Viking life science results (1977), and the Martian meteorite (1999), scientists will be reluctant to propose the experiments needed to confirm life on Mars. Who will risk having their career ruined by critics rejecting all data indicating life as illusionary patterns, chemical reactions, equipment artifacts, or contamination? Even if we send humans to Mars to observe microbes in action, someone will claim it is a hoax designed to boost NASA’s budget (which we should do anyway)! Hopefully, young scientists like Ojha will continue their important investigations so we can better prepare for life (native or transplanted) on the Red Planet.

The second printing of Welcome to Mars has been updated with changes to pages 12 and 70 reflecting the discovery of liquid water on Mars. What it means to the future settlers of Mars is up to them to decide!

Writing about Space

If your kids like Welcome to Mars, they might also like The Callahan Kids: Tales of Life on Mars. This is a collection of nine original stories about the first kids (ages 11 to 14) on Mars. All the stories had their science facts checked by engineers. Read the first story (by yours truly) FREE via the link on my website. EBook is $4.99 and print books are $9.00 if you use the 10 percent off code in the right-hand column.

Friday, February 19, Dinner at 6:30. Featured speaker for “Dinner with a Slice of History,” International Women in Air & Space Museum, Burke Lakefront Airport, 1501 North Marginal Road, Cleveland, OH 44114. Tickets $17. Book sales benefit the museum.

First week of March: I’ll be in Indialantic, Florida (near Melbourne) for a family reunion and would love to visit schools, libraries, astronomy clubs, women’s groups, churches, or book clubs to talk about space. Send email with contact info, and I’ll follow up.

Hello, and a special welcome to those of you who joined my monthly mailing list/newsletter at my book signing and talk to the NASA Alumni League at JSC on November 5. I call it Science Snacks because I discuss one cool science fact or news item (the “snack”) in each issue that I hope writers and readers of science fact & fiction will enjoy. This month’s topic is freefall.

“When you see astronauts floating in space on TV, it is easy to think there is no gravity there. But really there is. In fact, if you built a tower more than 200 miles (322 km) tall, as high as the space station’s orbit, gravity would be about 90 percent as strong at the top of the tower as on the ground. If you stepped off the top of the tower, you would drop to Earth. So why doesn’t the space station fall to Earth?”

Space Station Science, page 20

Say NO to zero G!

Since Space Station Science: Life in Freefall, was originally published in 1999, I have spoken to tens of thousands of students. When I toss a ball up in the air and ask why it falls down, the students have no problem answering that gravity pulls it down. Then I ask why the space station stays in orbit, and always someone shouts that it is because there is no gravity in space. I then ask them to raise their hands if they think there is no gravity in space. When I first started speaking at schools, about half the hands would go up. The rest admitted they didn’t know. Now almost all the hands shoot up, even those of the teachers.

There is in fact no such thing as “zero g” despite the insidious use of this unfortunate term. The force of gravity is LESS the farther you get from the center of the large mass that is pulling on you by the square of the distance you are from it. But it never goes to zero! (At the center of the Earth, the mass would pull you equally in all directions, so it may be “as if” there is no gravity, but you are still subject to Earth’s gravity, and the sun’s gravity, etc.)

The force of gravity at the Earth’s surface is 1g=GMm/D² where M is Earth’s mass, m is your mass, and D is 4000 miles, the radius of Earth. If you divide gravity at the surface by gravity 200 miles above the surface, all the terms cancel out except for D². So 4000 x 4000 divided by 4200 x 4200= 16,000,000/17,640,000 or 0.90. Thus, a person on a platform 200 miles up weighs 90 percent of what they weigh on the surface.

Why then, do astronauts float in space? The answer: because they are falling!

To demonstrate this at schools, I hold my space duck out beside me and ask the kids to imagine that we are skydiving. We step out of the plane together. Gravity immediately pulls us down. We appear to be floating next to each other as we fall at the same rate. Things float in space because they are falling.

But unless we deploy our parachutes, we will hit the ground. (I address the misconception that heavy things fall faster by dropping two plastic containers, one empty and one full of coins and letting them see they hit at the same time. I explain that falling in air depends on shape, not mass. I reference the Apollo 15 demo of the feather and hammer and note that their shapes didn’t matter because there is no air on the Moon. So if the space station is falling, whether in air or not, why doesn’t it hit the ground?

To demonstrate the answer, I have a little toy sponge shuttle on a string. I toss it up and it falls back down, gravity is pulling it down. Then I spin it around in a circle and say that gravity is like the string. As long as the space ship is high enough that it won’t run into anything (including air that slows it down) and continues going fast enough (about 5 miles a second), it can balance gravity. But if it slows down, it falls to the ground. That’s how we return from space: we slow down by firing engines and using friction with the air (and our shape to increase that friction).

It is far harder to undo a misconception than to explain that things float because they are falling. So please do your part to promote science literacy and ban the use of the term “zero g” from your lexicon! Practice saying, “When in FREEFALL, everything floats!”

Hello, and a special welcome to those of you who joined my monthly mailing list/newsletter at the Freeman Library Book Fair and at the SCBWI Houston meeting December 5th and 7th. I call it Science Snacks because I discuss one cool science fact or news item (the “snack”) in each issue that I hope writers and readers of science fact & fiction will enjoy. This month’s topic is observing the Moon.

“The near side [of the Moon] is the likely choice for the first lunar outposts. … All the Apollo landings were on the near side. Experience gained from these missions reduces the risk of some unexpected danger.”

Home on the Moon, page 40

Give Them the Moon

The Apollo Program “gave” me the Moon, and with it, a longing to explore space. I’m ever grateful for this gift which I first “opened” on Christmas Eve in 1968 when Apollo 8, the first human ship to orbit the Moon, sent back the famous image called “Earthrise,” showing the fragile blue home planet with the Moon’s stark surface in the foreground. During the following four years, six Apollo missions landed on that surface, forever changing what I see when I view a full Moon now: the places where they landed.

This year, we are all given the gift of a full Moon on Christmas. I urge you to go out and “unwrap” this gift. Using the simple memory aide I created as an activity for Odyssey magazine years ago, you can “open” this gift with the knowledge of where the Apollo missions landed (and impress all your relatives!).

Grab a friend or family member and go outside after dark on Christmas Eve or Christmas Day. The Moon will rise in the east around sunset and be overhead at midnight. First, identify the major features which are the dark maria or “seas.” For naked eye US observers, a very round dark spot on the right edge (which may point “down” at sunset) is the Sea of Crisis near the eastern equator. The left or western side of the Moon is generally dark (the Ocean of Storms). The left “eye” is called the Sea of Rains and beside it is the Sea of Serenity which is somewhat smaller. To the right and south and about the same size as Serenity is the famous Sea of Tranquility, where Apollo 11 landed.

Use your imagination to think of Serenity as the body, and Tranquility as the head of an upside-down “peace sign” rabbit, with two dark “finger ears” (Sea of Nectar and Sea of Fertility) pointing south. Apollo 11 landed near the equator right about where the Sea of Nectar connects.

Next note the bright white spot below the Sea of Rains. This is the crater Copernicus. Apollo’s 12 and 14 are south of it on either side and near the equator. In your mind, draw a line from 11 to 12 and 14. (Note, Apollo 13 didn’t make it to the Moon, but you can download the movie!) This is your “baseline” equator. Next draw a line from 14 up to a point between the eyes of Rains and Serenity. This is the bridge of the Moon’s nose and marks where Apollo 15 landed.

Now draw a line from Apollo 15 to below the equator in the whiter highland area across from the “kink” in the rabbit’s ear (Nectar). This is the site of Apollo 16. Finally, draw a line from there, past Apollo 11, up to the “top” side of the “neck” between the body (Serenity) and head (Tranquility) of the rabbit where Apollo 17 landed.

You have now connected the dots of all the Apollo landing sites in order from Apollo 11 to 17 and drawn a letter “N” for nose on the Moon! My son created an animated Moon Map for my website which includes this activity and also information on the features named.

I hope you will enjoy “opening” and sharing this celestial gift with your friends and family this holiday season. Happy New Year to everyone!

Writing about Space

The index for my memoir, A Passion for Space, has been updated with the correct page numbers. The new index is available free via Springer. Copies purchased after November have the updated index. The book is available via Springer and Amazon.

My short story, “The Right of Interference,” is included in the anthology, Touching the Face of the Cosmos: On the Intersection of Space Travel and Religion & is now available for order via Amazon.

Hello, and a special welcome to those of you joined my monthly mailing list/newsletter at the book signing with Buzz Aldrin at JSC on October 2. I call it Science Snacks because I discuss one cool science fact or news item (the “snack”) in each issue that I think other writers and readers of science fact & fiction will enjoy.

“I knew it was hopeless, but I tried firing up the communications array. No signal, of course. The primary satellite dish had broken off … The Hab had secondary and tertiary communications systems, but they were both just for talking to the MAV (Mars Ascent Vehicle), which would use its much more powerful systems to relay to Hermes. Thing is, that only works if the MAV is still around… I have no way to communicate with Hermes or Earth.”

The Martian by Andy Weir, Chapter 1

Communications Failure in The Martian Realistic?

The loss of communications plays a critical role in The Martian. As someone who loves to poke holes in movie “science,” I had to ask myself, is it a viable premise that Mark Watney is left with no way to communicate with Earth? Well, not really given that no Martian dust storm would ever have winds strong enough to knock out the primary antenna which author Andy Weir says, “acted like a parachute, getting torn from its foundation and carried with the torrent.” It also wouldn’t be buried in sand which (you geologists correct me if I’m wrong) is too heavy to be picked up by Martian wind in such quantity. The wind is also insufficient to knock over the MAV, which, being critical hardware, would be designed with this in mind if it were true!

But those of us who have worked real flights know that despite all our contingency plans, training, and malfunction procedures, things fail, explode, melt, freeze, or just plain refuse to function. And communications systems are notorious for finding creative new ways to not work. Shoot, even if the communications systems work, computers (also notoriously creative in failure modes) can keep them from delivering any meaningful data. Certainly no one anticipated the fire that took out the Mission Operations Computer during STS-5, severing all communications with the orbiter (at a time when the backup MOC was also down). If communications weren’t restored within about three hours, because of Columbia’s deteriorating state vector which required communications to update, the crew might have had to do an emergency landing in Africa.

What, you never heard about this near-miss abort? You can blame that on communication failures, too. Public Affairs decided not to bother the news media until after the smoke cleared, literally. This aspect of communications is also reflected in The Martian when NASA decides not to release the data about Watney being alive until they have a rescue plan to offer.

To restore communications, Watney (played by Matt Damon) treks to the Pathfinder site to retrieve its hardware. He first uses a Yes/No/? system and then devises a clever way for the camera to rotate in a circle marked off with the numbers 1-9 and letters A-F to represent the alphabet in hexadecimal code (41 is A, 5A is Z). Engineers back at JPL figure out what he’s up to and get the old Pathfinder out of storage. During the STS-5 fire, we created our own version of the Yes/No/? communications using the teleprinter, a single font, one-line-at-a-time teletype we flew on the early flights. Unlike voice and data, it didn’t require the MOC. We readied a one-way message to send the crew if necessary. The INCO team (led by Bob Castle) prepared an actual (just like the movie!) hexadecimal message that could be read up through one of the ground stations to have the crew manually clear the state vector alarm.

During STS-5, the Ground Control team was able to get the MOC restored with two minutes to spare. And Watney, thanks to his knowledge of how things work and trusting that Mission Control would be listening, is able to restore communications. Was this believable? Absolutely! (Which of you would be the one with a printout of hex code in your bag?!)

There’s more about the STS-5 fire in my memoir, A Passion for Space: Adventures of a Pioneering Female NASA Flight Controller which is now available in eBook and print from Springer and Amazon or through my website or at one of my events (see below).If you want to discuss other aspects of The Martian, please find me on Facebook!

If there is a particular science topic you’d like me to address in a future Science Snacks, please send me an email. Note, you can order copies of my books via Amazon or autographed copies via my website.